Blended hydraulic cement for both general and special applications

ABSTRACT

A blended hydraulic cement binder, is disclosed, consisting of water, fly ash, Type III portland cement, Type I portland cement, slag cement, ground silica, boric acid, borax, citric acid and an alkali metal activator. The cement binder and sequences for mixing the composition, is particularly useful because it provides: time to mix all components adequately, unrestricted transporting time that can be terminated, at will, followed by alterable placement and finishing times. The cement binder can be used as a neat cement or it can be extended with fillers, such as sand and gravel, to make mortar or concrete, that rapidly gains very high structural strengths.

This application is a continuation-in-part of application Ser. No. 08/066,702, filed May 27, 1993, now U.S. Pat. No. 5,374,308 and application Ser. No. 08/267,590, filed Jun. 29, 1994, now U.S. Pat. No.5,387,283.

FIELD OF THE INVENTION

High early strength, blended hydraulic cements, mixed in and activated by water, to form neat cements, or extended with aggregates to make concrete and mortar, have become essential building materials for today's construction industry.

BACKGROUND OF THE INVENTION

The hydraulic cement industry has utilized, in cement formulations, various ashes which are essentially waste products or by-products of production processes for several desired goals, the most obvious of which is to utilize an ever-growing source of material while at the same time lessening the ecological burden. Prior art has continued this evolution to the point of development of cement binders made exclusively from ash materials, with little or no portland cement as a constituent. What has evolved are high early strength hydraulic cements that are used for limited special applications.

These mineral binders and their progeny, have been developed with emphasis on dry interground or interblended formulation which is then mixed in water to produce an activated binder. The problem of intergrinding or interblending presents itself in the form of increased cost because of the need to transport the raw materials for making the binder to a central location where the grinding and manufacturing can take place.

The formulations of these prior art binders present a number of difficulties and limitations to the user. In each, there is an inherent failing: the water which is introduced into the binder material is needed to serve the purpose of properly dissolving and dispersing each element of the composition so that it may interact with the balance of the elements; however, the hydration reaction which is the ultimate goal begins to occur at the moment the water is introduced. When the objective is to produce high early strength cements, the problem of mixing is compounded by the need to include accelerators, activators, and retarders. Not only does the hydration reaction begin with the addition of water, but the water is also what starts the accelerators, activators, and retarders to interact with one another, and, the cementitious components, thereby affecting how fast or how slow the hydration proceeds. This prior art method, with limited amount of time, presents difficulty when the binder is put to practical applications. The user has an ever-decreasing amount of time to mix, transport and place the material properly. Time is so short that on-site mixing becomes imperative and only special applications that can afford the extra cost involved can use these cements. Although recent developed cements have provided high early strengths, the loss of working time was an unfortunate consequence of what was accomplished. Such cements are described in Heitzmann et al., U.S. Pat. No. 4,842,649, issued Jun. 27, 1989, and Gravitt et al., U.S. Pat. No. 4,997,484, issued Mar. 5, 1991, respectively.

Further, these prior art cement binders exhibit a premature exothermic reaction during mixing as portions of the binder agglomerate or "ball". When these binders are used for making structural mortars and concretes on a large scale (such as in a ready-mix truck or an industrial batch operation), agglomeration or "balling" could have disastrous effects upon the equipment unless the mixer is only partially filled. After mixing for a few minutes the reaction subsides and the mix smoothes out.

All of the prior art high early strength cements, stress the necessity of low water/cement ratio, which results in low slump, and is difficult to place. Another consequence of low water/cement ratio is inadequate bleed water for the finisher to trowel the mixture properly.

Also the cement binder as described in U.S. Pat. No. 4,997,484, does not appear to provide adequate abrasion resistance for structural applications.

What prior art has not recognized is the value which each element of the composition can impart when introduced individually. Many prior art compositions contain material elements which are somewhat mutually exclusive, and are referred to in the prior art as retarders and activators or accelerators. Logic would not dictate that efficient use of either could be obtained by activating both at the same moment. This is particularly significant since some of the material components referred to by the industry as retarders actually provide significant additional functional value, undiscovered in prior art.

Prior art describes the use of citric acid as a retarder. The confusion over what role citric acid actually plays is probably the reason why previous attempts to control the hydration reaction of cements containing large quantities of subbituminous fly ash have had such erratic results. In the field of high percentage fly ash binders which are formulated as high early strength hydraulic cements, citric acid can play a role more aligned with an accelerator. Prior art usage has failed to recognize this phenomenon and consequently, in some cases has attempted to utilize citric acid as a retarder where the formulation design could only cause the citric acid used to exhibit itself as an accelerator. Such cement binders are described in U.S. Pat. No. 4,997,484, respectively.

Prior art has also failed to provide for a composition of material which would allow the user to control the initial set of the material at the location of use. The consequence of this failing, when considered together with the very limited amount of working time provided by prior art binders, is that they may only be used in special applications on a small scale. Since high volume use requires machinery intensive production processes, users require materials with a greater degree of flexibility in order to minimize the risks associated with cement binders producing high early strength hardened masses.

The present invention addresses the need for a rapid strength gaining, hydraulic cement by providing a composition of materials which are introduced by mixing sequences to provide:

1. time to mix all the ingredients properly,

2. unrestricted time to transport the mixture of cementitious components, water and aggregates with the ability to terminate the time when it is not needed,

3. high early strength cements with high slump mixes that are easy to place and finish, and,

4. placement and finishing time period that can be short or long depending on the applications, with the added flexibility, to make a selection at the job site.

A further method of this invention is to improve the physical properties of waste fly ash so they can be used more productively to create both general purpose as well as special application blended hydraulic cements by:

1. removing unburnt carbon, if it prevents the use of fly ash that contains excessive amounts,

2. improving the density to reduce the permeability, and,

3. increasing the abrasion resistance,

4. eliminating or minimizing alkali silica reactivity if the elements which contribute to this problem are present, and

5. creating a more durable, more cost-effective, general purpose, structural cement.

Prior art teaches away from the present invention when U.S. Pat. No. 4,842,649, states the order of mixing the various materials that make up the composition is immaterial, and, U.S. Pat. No. 4,997,484, states that all the components can be interground or interblended and that doing so eliminates the control problems that can occur.

SUMMARY

U.S. patent application Ser. No. 267,590 to be issued on Feb. 7, 1995 as U.S. Pat. No. 5,387,283 describes what is essentially a two step process for making a blended hydraulic cement for general or special applications composed of a composition of materials described in U.S. patent application Ser. No. 66,702, now issued as U.S. Pat. No. 5,374,308. During the processing of these applications, tests of this cement, made into concrete, were conducted by the U.S. Army Corps of Engineers (CORPS), for the Federal Highway Administration (FHWA), These tests assessed the durability, compressive strengths, and adjustable setting time of this new cement binder in comparison with Type III portland cement, which included short as well as long range water-reducing admixtures. The results of these tests are now being printed. In the interim, a copy of the final draft is made part of this file. The conclusions state on page 11, 9a that the cement of this invention had better control, better resistance to chloride permeability, better frost resistance even with low air contents, less shrinkage, and similar compressive strengths.

Durability of the materials, necessary to build and maintain our infrastructure, is critical when we can no longer afford the luxury of delays for recurring repairs in what is already a congested environment. But, increasing the durability of cost-sensitive construction materials is often difficult to implement, even when we recognize that, if included, certain elements would help. The reason is economics. Unless the improving elements do more than just add increased durability, it is extremely difficult to justify their additional cost when doing so would change the established cost structure. Long term cost effectiveness is difficult to sell. The desire to build more in a crowded environment too often takes precedence over the consequence of future rehabilitation and ultimate replacement. Whether or not lithium should be used in concrete is an excellent example. For over 40 years the industry has known lithium, if used in portland cement concrete subject to alkali-silica reactivity, could minimize or eliminate what can be the disastrous consequences of having to tear out and replace the entire structure in a few short years. As critical as it is, the additional cost to portland cement concrete has been difficult to justify; since, the cost of lithium hydroxide has recently been $3.00 per pound or $6,000 per ton; whereas, the recent cost of the portland cement it could benefit has been $0.03 per pound or $60.00 per ton. As a result, the industry has consistently elected not to buy the lithium insurance and instead employs other alternatives. Consequently, one of lithium's virtually unused benefits has been consistently bypassed by a cost constrained concrete industry.

It has long been known that lithium, rare among the earth's elements, is capable of providing many other unique and beneficial advantages ranging from life saving mental disorder drugs, to light weight metal alloys, to longer life batteries, even into space as an atmosphere regenerator and now to make concrete more durable. The largest individual obstacle, which impedes the otherwise rapid exploitation and increased use of lithium's expansive array of exceptional properties, continues to be cost. But, without a broad based, established, perpetual and growing market, the dramatic reduction in production costs, that can only be achieved by increasing production to enjoy the economy-of-scale, eludes the manufactures of lithium.

This application introduces lithium as another and even more effective alkali metal activator when used to make this blended hydraulic cement for both general and special applications. The advantages in using lithium as one of the alkali metal activators in this blended hydraulic cement are many. As a result, lithium becomes a more cost-effective alternative:

(1) The increased effectiveness of lithium as an alkali metal activator enables less quantity to be used; thereby, providing the maker of the cement with equal or better benefits at less cost.

(2) Since the alkali metal activator is accelerated with approximately an equal amount of citric acid accelerator, which has previously accounted for nearly half of the total cost of the chemical components, the ability to use less activator also enables the maker of the cement to use less accelerator which in turn further reduces the overall cost.

(3) Reducing the amount of the activator and accelerator in turn enables the set-suspending and modifying retarder to be reduced while still maintaining the desired amount of placement time.

(4) Since less volume of both the lithium activator and citric acid accelerator are required to terminate the set-suspended cementitious components, and these activating components must logically be transported to the point where the activation takes place, then both the size of the containers required, and the means to convey the chemical components can be reduced; thereby, enabling the maker of the cement to provide equal or better benefits at another reduction in cost.

(5) As Ex. 36 compared to Ex. 37, 38, 39 demonstrate, the combined use of the alkali metal activators enables the cement maker to substantially reduce the quantity of the activator and accelerator used to obtain increased placement time after activation instead of using more borax and boric acid which again further reduces the cost.

(6) Both sodium hydroxide and potassium hydroxide are extremely deliquescent. Storage and pneumatic conveyance of these materials must take this characteristic into account. Lithium hydroxide is not deliquescent.

(7) As revealed in the chloride permeability test included in the parent patents 5,387,283 and 5,374,308 and redone by the CORPS for the FHWA, this blended hydraulic cement mortar is exceptionally dense. It has long been known that adding lithium hydroxide and carbonate is an excellent means for making concrete less permeable. Less lithium will be required to obtain this benefit; because, a cement with a denser pore structure, as measured by its resistance to the passage of chloride, does not require as much water inhibiting agent to achieve equal or better resistance to permeability.

The use of lithium hydroxide and lithium carbonate as one of the alkali metal activators will enable this cement to reap the additional benefits of using this rare alkali metal, as the volume generated lowers the cost in this and other uses.

The following examples should be considered as illustrative only and not as limiting, in any way, the full scope of the invention as covered in the appended claims.

BRIEF DESCRIPTION OF THE INVENTION

The following components are used to make the blended hydraulic cement of the present invention for both general and special applications. The approximate amounts are:

(A) About 14.52 to 21.77 percent Water

(B) About 0.07 to 1.35 percent Boric acid

(C) About 0.15 to 2.95 percent Borax

(D) About 50.33 to 83.36 percent Subbituminous fly ash

(E) About 0 to 8.00 percent Type III portland cement

(F) About 0 to 16.00 percent Type I portland cement

(G) About 0 to 8.00 percent Slag cement

(H) About 0.04 to 11.05 percent Alkali metal activator

(I) About 0.04 to 2.85 percent Citric acid

(J) About 0 to 8.00 percent Ground silica

Pre-established amounts of the chemicals and minerals are optimized to provide the highest possible early strengths.

The method for making this blended hydraulic cement begins by dissolving inwater, component (B) or component (C), or (B) and (C) together. Whichever material component is used, it is used in sufficient quantity to prevent, as opposed to merely retard, the hydration of the components (D), (E), (F)or (G). Alternately, components (B) through (G) with or without component (J) and/or other aggregates can first be combined, then component (A) added, however doing so would require a slight increase in (B) and/or (C).If desired, inert aggregates, and other inert materials, such as component (J), may or may not be added at this time. Depending on the amount of components (B), (C), or (B) and (C) used, the partially made cement, with or without aggregate fillers, can be suspended/transported for minutes, hours, or several consecutive days. The suspension process can be terminated, at will, and the cement making process can be continued by adding the component (B), (if it was not previously added). Adding component (B) at this point in the mixing sequence, rather than dissolvingit with the component (C) in water, extends the placement time. The next order of mixing is to add either the component (H) or the component (I) that acts like an accelerator in the present invention, as opposed to being a retarder in prior art. Provided the ratio of component (B) used isnot greater than 33% of the combined components (B) and (C) used, adding the component (I) as the last component will cause the placement time to be longer. If the component (B) to component (C) ratio is as previously stated, adding (H) as the last component will shorten the placement time. Extremely long placement times can be obtained by the accumulative effect of adding the component (B) immediately before the component (H) and followed by the component (I). If component (B) is used by itself or the ratio of (B) to (C) is increased whereby (C) becomes the dominant component, the results obtained by the order of the last two components isreversed.

When the last chemical component is mixed and the cement is complete, sand to make mortar or sand and coarse aggregates to make concrete can be addedat this time, if they were not added during the cement making process. The ability to add aggregates at two different times will provide added benefits to the users of neat cement, mortar, or concrete while continuingto maintain the same established methods of the past.

A significant feature of the present invention is that the ratio of chemicals to the cementitious components is established to achieve the highest possible strengths and durability. Once the formulation is optimized for the particular fly ash that is being used, the quantity of components are not altered to achieve longer or shorter working times. Thevariations in placement time, which follows the transport/suspension time period, is achieved in the present invention by changing the order of introduction of the chemicals not their amounts. In addition, the amount of placement times can be fine tuned by using different quantities of separate types of portland cement or slag cement. Those skilled in the artknow that component (F) offers slower setting (placement) time than component (E). Component (G) in the present invention provides approximately the same amount of placement time as component (E). Therefore, when more of component (F) is used it would provide more placement time.

Those skilled in the art, will recognize that increasing the amount of portland cement or slag cement beyond the amount needed to provide abrasion resistance and less permeability will increase the cost in as much as the waste fly ash, which is responsible for providing the sulfate resistance, provides the same strength as the portland cement and slag cement for less cost. The large amount of fly ash used in the present invention helps offset the cost of the chemical components necessary to make the blended hydraulic cement of the present invention achieve high early and ultimate strengths with lasting durability.

In the present invention either the component (B) or component (C) can be eliminated, but not both. If there is no need to extend the placement timecomponent (C) can be used without component (B) if it is mixed with warm water, or as long as it can be dissolved in the small amount of water being used. At times this may be preferred since (C) is more readily available in large quantities. One may prefer to use component (B) withoutcomponent (C) because the small amount of water used is still sufficient for dissolving the amount of (B) that would normally be needed. Also the volume required is less than component (C). However, the cost of (B), per pound is higher than (C).

Prior art optimizes the amount of chemical components needed to provide thehighest possible strengths, then alters the established amounts to provide longer or shorter working times. The present invention optimizes the chemical amounts needed to provide the highest strengths possible, but does not alter these amounts to provide more or less placement time.

Ten different sequences are necessary in the present invention to provide the flexibility to handle all types of applications. These can range from applications that require no transport time to those needing a week or more. Placement times may be as short as a few seconds or as long as several hours. In addition, the mixing sequence provides an option that can be exercised by those placing the material to choose from various placement time periods. These are provided by the order in which the last components are introduced. Because of the ten different mixing sequences, all the above can be accomplished with a rapid curing cement, without sacrificing very high early strengths, or very high ultimate strengths. The high early strength, blended hydraulic cement of the present inventioncan be used interchangeably as a general purpose cement, or a cement capable of performing under very special conditions requiring precise timeperiods.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The essential components of the present invention to produce the blended hydraulic cement for both general and special applications, by weight, per100 percent total cement is as follows:

(A) About 14.52 to 21.77 percent Water

(B) About 0.07 to 1.35 percent Boric Acid

(C) About 0.15 to 2.95 percent Borax

(D) About 50.33 to 83.63 percent Subbituminous Fly Ash

(E) About 0 to 8.00 percent Type III Portland Cement

(F) About 0 to 16.00 percent Type I Portland Cement

(G) About 0 to 8.00 percent Slag Cement

(H) About 0.04 to 11.05 percent alkali metal activator

(I) About 0.04 to 2.85 percent Citric Acid

(J) About 0 to 8.00 percent Ground Silica

Either component (B) or component (C), or (B) and (C) together must be employed. The combined total of (E), (F), and (G) is not to be less than 5.00 percent of the total cement.

Since all the chemicals are soluble, or can be made soluble in water, and the minerals are as fine, or finer than portland cement, it is not necessary to intergrind or interblend any of them. This dramatically reduces the manufacturing cost and permits locally available materials to be used. However, the mixing sequence of the various material components which make up the composition is pivotal to the present invention.

(A) Water can be any potable water.

(B) Granular boric acid (H₃ BO₃), used by itself in the proper amount, suspends the hydration of the cementitious materials (D) through (G), inclusive. Boric acid will dissolve in the amount of water indicated.Used together with the alkaline borax, boric acid increases the solubility of the less soluble borax due to the formation of polyborates. The amount of boric acid used, governs the amount of borax used as either one is capable of suspending the hydration of the cementitious materials (D) through (G), inclusive. The preferred amount of boric acid to be employed is between 0.07 to 1.25 percent by weight.

One of the most remarkable and rewarding discoveries made in the present invention, completely contradicts teachings found in prior art cement patents. When used in conjunction with the other components in the cement,boric acid has the ability to provide variable placement times solely basedupon the timing of its introduction into the mix. In addition to suspendingand helping to establish variable placement time frames, boric acid, together with borax, tempers the subbituminous fly ash, improving the high-early strength gain. Boric acid can be obtained from the United States Borax Corporation.

(C) Borax 5 Mole or borax 10 Mole can be used in granular or powdered form.The preferred amount of borax to be employed is between 0.15 to 2.80 percent, by weight of 10 mole borax. At the lower percent the suspension will not hold for more than 24 hours. When 2.5 percent is employed the borax will suspend the prescribed amount of cementitious materials for an indefinite time. It is preferable to use the borax in combination with boric acid so that variable control over placement time can be exercised. Granular borax (Na₂ B₄ O₇.10H₂ O), in the amount required is not soluble in the limited amount of water needed to make highstrength concrete unless it is combined with boric acid, or the water is heated. (Solubility table is provided) It gives strength to the cement being formed and helps prevent cracking.

Borax, when mixed with water and cementitious components (D) through (G), inclusive, causes the mix to remain fluid until the last cement making components are added.

(D) Subbituminous fly ash comes from coal burning electric power plants that burn subbituminous coal. This particular fly ash is high in calcium oxide, and is included in the ASTM designation C618 as a Class C fly ash. The volume of subbituminous material available is increasing rapidly because it has the lowest emission rating of all the coals that are burned. One skilled in the art will appreciate, how the method of combining the components, enables the various fly ashes from different plants to be easily adapted. Several electric generating, coal burning power plants, such as Houston Light and Power can furnish this type fly ash.

(E) & (F) Type III Portland Cement and Type I Portland Cement are the preferred mineral admixtures employed in this present invention to impart greater density, and abrasion resistance. This is achieved because the particle size, being slightly larger than fly ash, enables the compositionof materials to compact. Portland cements would be readily available for those who would use the cement. Each Type has a different set time. Varying the amount of each one used helps fine-tune the exact time of placement, which could be critical in making rapid setting concrete products on high speed production lines. Any portland cement manufactured to meet the ASTM standard C150 is acceptable. The portland cement does notappear to add to or reduce the strengths that are obtained. In addition allTypes, or a blend of types, will increase the abrasion resistance and reduce the permeability of the hardened mass. Any portland cement manufacturer, such as LaFarge Corporation, can furnish the types of cements needed.

(G) Any ground slag, which complies with ASTM standard C989, can be employed in this present invention. Slag is used in conjunction with or asa substitute for the Type I or Type III portland cements listed above and imparts the same qualities insofar as abrasion resistance or durability isconcerned, and in addition slag provides some glassy silicate components and creates a less permeable mixture. The effect on placement time is similar to Type III portland cement. Slag cement can be obtained from BlueCircle Cement Company.

(H) Lithiuroxide (LiOH), is the preferred alkali metal activator when only one activator is used because it imparts the highest level of durability and is a more effecive activator for the volume needed. When used in conjunction lithium hydroxide and potassium hydroxide(KOH), are preferred when very high strengths are required and a small volume of activator is preferrable. The combination of potassium hydroxide and sodium carbonate would be preferred when extended set times are desirable and the durability would otherwise provide is not needed. Lithium hydroxide and sodium carbonate can be obtained from FMC Corporation and others. Potassium hydroxide can be obtained from Occidental Chemical and others.

(I) Citric acid (HOOCCH₂ C(COH)(COOH)CH₂ COOH), can be used in any of its available grades, including fine crystal, liquid or powder. Additionally, salts of citric acid can be used in place of the citric aciditself. Citric acid is a known retarder for aluminate phases in portland cement, calcium fluoroaluminate, and calcium aluminate cements. In the composition of the present invention the citric acid does not act as a retarder to delay the hydration reactions, but remarkably acts as an accelerator. This discovery together with the previous discussed discoveryregarding boric acid, made it possible to alter the placement time, depending on when the citric acid and boric acid are introduced into the system. It is recognized citric acid can be diluted in water before the cementitious components are added. Doing so causes erratic strength development and makes it impossible to take advantage of many of the variable time periods of the present invention because it will severely shorten the placement time. Citric acid can be obtained from many producers such as Miles, Inc.

(J) Ground Silica sold under the registered trade name of SIL-CO-SIL number250 is preferred, however, any substantially equivalent ground silica may be used. It is entirely optional to the present invention; however, it adds to the density, which improves the durability, of the hardened mass. It helps increase the abrasion resistance and lowers the permeability. Theground silica does not change the transport time, but most remarkably, it reduces the time before set, and does increase the rapid strength gain. Ifgreater rapid strength gain and increased durability were not considerations, the ground silica could be omitted, however, in the present invention it is preferred. Ground silica can be obtained from U.S.Silica Company.

TIME PERIODS

Prior art refers to one (1) time period which is alternately called: working time, open time, plasticity, or workability. It is defined as the total time which starts when water first comes in contact with the cement,and ends when the cement, concrete, or mortar, can no longer be troweled orotherwise shaped. The present invention refers to four (4) time periods. They are:

1. Mixing Time, Includes approximately 2 minutes to dissolve components (B)and/or (C) in the water, and is never less than 5 minutes for any remainingone, or a combination of cement components, to be mixed properly,

2. Transport Time, which begins after the cementitious components (D) through (G), inclusive, have been introduced into the mix water and is terminated, as the user may elect, when the final cement making components(H) through (J) are added,

3. Placement Time, which begins when the transport time ends, and the remaining cement making components (H) through (J) have each been mixed for 5 minutes, or if mixed together, for a total of 5 minutes,

4. Total Work Time, is the sum total of the mixing time, transport time, and placement time of the present invention. It is the same time period prior art calls: "working time", "open time", "plasticity", or "workability".

MIXING SEQUENCES FOR MAKING THE BLENDED HYDRAULIC CEMENTS AND ALTERING THEIR PLACEMENT TIMES

The present invention utilizes any one of the following mixing sequences:

    ______________________________________                                         Mixing sequence 1 Mixing sequence 2                                            ______________________________________                                         1 Water           1 Water                                                      " Boric acid      " Boric acid                                                 " Borax           " Borax                                                      2 Subbituminous fly ash                                                                          2 Subbituminous fly ash                                      " Type III portland cement                                                                       " Type III portland cement                                   " Type I portland cement                                                                         " Type I portland cement                                     " Slag cement     " Slag cement                                                3 Ground silica   3 Ground silica                                              4 Potassium hydroxide                                                                            4 Citric acid                                                5 Citric acid     5 Potassium hydroxide                                        ______________________________________                                         Mixing sequence 3 Mixing sequence 4                                            ______________________________________                                         1 Water           1 Water                                                      " Borax           " Borax                                                      2 Subbituminous fly ash                                                                          2 Subbituminous fly ash                                      " Type III portland cement                                                                       " Type III portland cement                                   " Type I portland cement                                                                         " Type I portland cement                                     " Slag cement     " Slag cement                                                3 Ground silica   3 Ground silica                                              4 Boric acid      4 Boric acid                                                 5 Potassium hydroxide                                                                            5 Citric acid                                                6 Citric acid     6 Potassium hydroxide                                        ______________________________________                                         Mixing sequence 5 Mixing sequence 6                                            ______________________________________                                         1 Water           1 Water                                                      " Boric acid      " Boric acid                                                 2 Subbituminous fly ash                                                                          2 Subbituminous fly ash                                      " Type III portland cement                                                                       " Type III portland cement                                   " Type I portland cement                                                                         " Type I portland cement                                     " Slag cement     " Slag cement                                                3 Ground silica   3 Ground silica                                              4 Potassium hydroxide                                                                            4 Citric acid                                                5 Citric acid     5 Potassium hydroxide                                        ______________________________________                                         Mixing sequence 7 Mixing sequence 8                                            ______________________________________                                         1 Water           1 Water                                                      " Borax           " Borax                                                      2 Subbituminous fly ash                                                                          2 Subbituminous fly ash                                      " Type III portland cement                                                                       " Type III portland cement                                   " Type I portland cement                                                                         " Type I portland cement                                     " Slag cement     " Slag cement                                                3 Ground silica   3 Ground silica                                              4 Potassium hydroxide                                                                            4 Citric acid                                                5 Citric acid     5 Potassium hydroxide                                        ______________________________________                                         Mixing sequence 9 Mixing sequence 10                                           ______________________________________                                         1 Water           1 Water                                                      " Boric acid      " Borax                                                      " Borax           2 Subbituminous fly ash                                      2 Subbituminous fly ash                                                                          " Type III portland cement                                   " Type III portland cement                                                                       " Type I portland cement                                     " Type I portland cement                                                                         " Slag cement                                                " Slag cement     3 Ground silica                                              3 Ground silica   4 Boric acid, together                                       4 Citric acid, together                                                                          with Citric acid, &                                          with Potassium hydroxide                                                                         Potassium hydroxide                                          ______________________________________                                         Several other unique characteristics of the present invention are exhibited     in certain of the mix designs and mixing sequences:

(i) When material component (B) alone, or material component (B) and (C) together have been introduced into the water followed only by material component (D), the free carbon in the fly ash is released and floats to the surface during the mixing process. The occurrence of this phenomenon allows the user to collect and remove the excess carbon. The mixing actioncauses the carbon to be thrown to the sides of the mixer. There it collectsin a ring above the mixture of fly ash, boric acid and water provided the sides of the mixer are slightly tapered.

(ii) Material component (B) when employed alone, or material component (B) and (C) when employed together, will cause the material components (D) through (G), inclusive, to congeal or coagulate if the mixing sequence is suspended and allowed to remain stationary, after the introduction of the last material component of (E), (F) of (G). When the user introduces energy into the mix and then adds the remaining components, the congealed mixture will again become very fluid. Example Nos. 33 and 34 take advantage of this phenomenon. This feature of the present invention allowsthe user to produce a two-part blended cement binder where the two parts are separated by a pouch, or where one of the parts is packaged separately, for the ultimate user to simply mix and use. This enables the cement of the present invention to eliminate the need for precise measurement of water on the job site, where water is often difficult to obtain, and workers are sometimes not able to measure accurately.

(iii) As long as energy is added to the mixture, the material component (B)together with components (H) and (I) causes the mixture to become highly fluid, enabling the user to pour the material rather than place it. Then several minutes before the placement and finishing time is lost component (B) causes the mixture to thicken and become very plastic. This allows thematerial to be used in a self-leveling form then be easily troweled and shaped.

(iv) Material components (B) and (C) each impart a soapy, non-sticky characteristic to the mixture which can be very desirable to the user. When the material components (A) through (G), inclusive, are mixed and theuser desires to pump or extrude or convey the mix through any of many mechanical applications (prior to the introduction of the remaining material components), the suspended materials can be so handled without the risk of premature set in the equipment.

Unlike prior art, the METHOD for making the blended cement of the present invention, provides, not one, but two different introduction points where the fillers, such as sand and gravel, can be added to the cement to make concrete and mortar. Users of general and special application ready mixed mortar and concrete will find this feature of great benefit, since controlof delivered product will be exercised at the point of application and use.In the above 10 mixing sequence examples, aggregates to make mortar or concrete may be added after the cementitious components (D) through (G), inclusive, have been mixed, together with or without the ground silica, oralternatively, may be added after the last blended cement making component is mixed.

In the examples that follow, when fillers are added, they are not part of the cement being formed. They are shown to demonstrate how the versatilityof including fillers can be accomplished, and how this versatility can be used advantageously.

In the following examples the neat cement, mortar or concrete tests were placed in 2" cube molds, or in the case of concrete were placed in cylinders and allowed to hydrate. Periodic tests were conducted to determine how long the material remained trowelable. After the samples cured, they were demolded and broken under compression at the various timeperiods shown.

The following are given as examples of formulations of the blended hydraulic cement of the present invention. They should be considered as illustrative only and not as limiting, in any way, the full scope of the invention as covered in the appended claims. All percentages are by weight. There is a column provided which shows the percentage of all components, including water and ground silica and a separate column showing the percentage of all chemicals and cementitious components only. The ratio of water to the cementitious and chemical components is shown separately and excludes the ground silica.

EXAMPLE 1

(Mixing sequence 1)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   621    18.75                Water     1ST                                      21.00  0.63     0.85        Boric acid                                                                               "                                        69.51  2.10     2.80        Borax     "                                        2100   63.41    84.63       Fly ash   2ND                                      105    3.17     4.23        P.C. III  "                                        105    3.17     4.23        P.C. I    "                                        210    6.34                 Ground silica                                                                            3RD                                                                            STEP 2                                   38.49  1.16     1.55        KOH       4TH                                      42.00  1.27     1.69        Citric acid                                                                              5TH                                      Water/cement ratio: 0.25                                                                            1 day   3,989   p.s.i.                                    Mixing Time:       22 mins.  3 day 7,072 "                                     Transport.Time:                                                                           2 hrs    0 mins.  7 day 8,373 "                                     Placement Time:                                                                           3 hrs    0 mins. 14 day 9,052 "                                     Total Work Time:                                                                          5 hrs   22 mins. 28 day 10,113                                                                               "                                     ______________________________________                                    

After the ground silica was added, the partially made cement was held 2 hours(transport time). Then 3789 grams of sand and 4899 grams of gravel were added to make concrete after the last two cement making components were mixed.

EXAMPLE 2

(Mixing sequence 1)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    17.81                Water     1ST                                      9      0.64     0.85        Boric acid                                                                               "                                        30     2.14     2.82        Borax     "                                        900    64.13    84.63       Fly ash   2ND                                      45     3.21     4.23        P.C. III  "                                        45     3.21     4.23        P.C. I    "                                        90     6.41                 Ground silica                                                                            3RD                                                                            STEP 2                                   16.5   1.18     1.55        KOH       4TH                                      18     1.28     1.69        Citric acid                                                                              5TH                                      Water/cement ratio: 0.24(ex.silica)                                                                 1 day    6,625  p.s.i.                                    Mixing Time:       22 min.   3 day  8,625                                                                               "                                     Transport Time:                                                                           21 hrs  30 min.   7 day 11,125                                                                               "                                     Placement Time:    30 min.  14 day 11,500                                                                               "                                     Total Work Time:                                                                          22 hrs  22 min.  28 day 13,500                                                                               "                                     ______________________________________                                    

To make mortar 810 grams of sand were added, together with the ground silica. The partially made cement was held for 21 hours and 30 minutes(transport time). After the transport time the last two cement making components were mixed.

This cement was made again into a mortar following the same procedure. A test cylinder was made and the cylinder was subjected to a:

    ______________________________________                                         Rapid chloride permeability test                                               (28 days) AASHTO T-277                                                         Result - 302 Coulombs                                                          SHRINKAGE TESTS                                                                (According to: ASTM C-157)                                                     Initial reading at 2 hours                                                                       Initial reading at 24 hours                                  ______________________________________                                          6 hours  0.014%       8 days   0.031%                                          1 day    0.063%      14 days   0.039%                                          8 days   0.094%      28 days   0.063%                                         14 days   0.102%                                                               28 days   0.126%                                                               ______________________________________                                    

EXAMPLE 3

(Mixing sequence 2)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    17.81                Water     1ST                                      9      0.64     0.85        Boric acid                                                                               "                                        30     2.14     2.82        Borax     "                                        900    64.13    84.63       Fly ash   2ND                                      45     3.21     4.23        P.C. III  "                                        45     3.21     4.23        P.C. I    "                                        90     6.41                 Ground silica                                                                            3RD                                                                            STEP 2                                   18     1.28     1.69        Citric acid                                                                              4TH                                      16.5   1.18     1.55        KOH       5TH                                      Water/cement ratio: 0.24(ex.silica)                                                                 1 day    7,625  p.s.i.                                    Mixing Time:       22 min.   3 day  9,000                                                                               "                                     Transport Time:    0         7 day  9,625                                                                               "                                     Placement Time:    35 min.  14 day 12,000                                                                               "                                     Total Work Time.   57 min.  28 day 12,000                                                                               "                                     ______________________________________                                    

To make mortar 810 grams of sand were added together with the 90 grams of ground silica, after the cementitious components were mixed, and before the citric acid was mixed.

EXAMPLE 4

(Mixing sequence 2)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   621    18.75                Water     1ST                                      21     0.63     0.85        Boric acid                                                                               "                                        69.51  2.10     2.80        Borax     "                                        2100   63.41    84.63       Fly ash   2ND                                      105    3.17     4.23        P.C. III  "                                        105    3.17     4.23        P.C. I    "                                        210    6.34                 Ground silica                                                                            3RD                                                                            STEP 2                                   42     1.27     1.69        Citric acid                                                                              4TH                                      38.49  1.16     1.55        KOH       5TH                                      Water/cement ratio: 0.25                                                                            1 day   4,243   p.s.i.                                    Mixing Time:       22 mins.  3 day 7,256 "                                     Transport Time:                                                                           2 hrs    0 mins.  7 day 9,052 "                                     Placement Time:                                                                           1 hr     0 mins. 14 day 9,102 "                                     Total Work Time:                                                                          3 hrs   22 mins  28 day 10,042                                                                               "                                     ______________________________________                                    

After the cementitious components were mixed the partially made cement and fillers were held for 2 hours(transport time). During this time the 210 grams of ground silica, 3789 grams of sand, and 4899 grams of gravel were included, to make concrete after the last two cement components were mixed.

EXAMPLE 5

(Mixing sequence 3)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    18.06                Warm Water                                                                               1ST                                      15     1.08     1.44        Borax     "                                        900    65.03    86.21       Fly ash   2ND                                      45     3.25     4.31        P.C. III  "                                        45     3.25     4.31        P.C. I    "                                        90     6.50                 Ground silica                                                                            3RD                                                                            STEP 2                                   4.5    0.33     0.43        Boric acid                                                                               4TH                                      16.5   1.19     1.58        KOH       5TH                                      18     1.30     1.72        Citric acid                                                                              6TH                                      Water/cement ratio: 0.24(ex.silica)                                                                 1 day    6,675  p.s.i.                                    Mixing Time:       27 min.   3 day  8,500                                                                               "                                     Transport Time:     0 min.   7 day  9,113                                                                               "                                     Placement Time:    30 min.  14 day 10,688                                                                               "                                     Total Work Time:   57 min.  28 day 11,450                                                                               "                                     ______________________________________                                    

Inasmuch as the boric acid used was introduced after the cementitious materials were mixed the 0.24 water/cement ratio would not dissolve the 1.43 parts of borax unless the water was heated.

The introduction of the boric acid immediately preceding the potassium hydroxide and citric acid instead of mixing it with borax provides a longer placement time.

To make mortar 810 grams were added with the ground silica.

EXAMPLE 6

(Mixing sequence 3)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   621    18.75                Warm Water                                                                               1ST                                      69.51  2.10     2.80        Borax     "                                        2100   63.41    84.63       Fly ash   2ND                                      105    3.17     4.23        P.C. III  "                                        105    3.17     4.23        P.C. I    "                                                                              STEP 2                                   210    6.34                 Ground silica                                                                            3RD                                      21.00  0.63     0.85        Boric acid                                                                               4TH                                      38.49  1.16     1.55        KOH       5TH                                      49.00  1.27     1.69        Citric acid                                                                              6TH                                      Water/cement ratio: 0.25                                                                            1 day   4,243   p.s.i.                                    Mixing Time:       27 min.   2 day 7,178 "                                     Transport Time:                                                                           16 hrs  50 min.   7 day 8,345 "                                     Placement Time:    49 min.  14 day 9,123 "                                     Total Work Time:                                                                          18 hrs  06 min.  28 day 9,760 "                                     ______________________________________                                    

At the time ground silica was included, 3789 grams of sand and 4899 grams of gravel were added to make concrete after the last three components weremixed.

Although the partially, made cement was held 16 hours and 50 minutes(transport time), the cement still provided 49 minutes placement time, because the boric acid was introduced just before the final two cement components were mixed.

EXAMPLE 7

(Mixing sequence 3)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    17.51                Warm water                                                                               1ST                                      40     2.80     3.68        Borax     "                                        900    63.05    82.76       Fly ash   2ND                                      45     3.15     4.14        P.C. III  "                                        45     3.15     4.14        P.C. I    "                                        90     6.30                 Ground silica                                                                            3RD                                                                            STEP 2                                   11.88  0.83     1.09        Boric acid                                                                               4TH                                      21.8   1.53     2.00        KOH       5TH                                      23.8   1.67     2.19        Citric acid                                                                              6TH                                      Water/cement ratio: 0.18                                                                            1 day    6,000  p.s.i.                                    Mixing Time:       27 min.   3 day  8,000                                                                               "                                     Transport Time:                                                                           67 hrs. 15 min.   7 day 10,875                                                                               "                                     Placement Time:                                                                            4 hrs. 40 min.  14 day 11,625                                                                               "                                     Total Work Time:                                                                          72 hrs. 22 min.  28 day 11,875                                                                               "                                     ______________________________________                                    

After the ground silica was mixed the process for making the cement was suspended 67 hours and 15 minutes. Just before last three components were mixed, 810 grams of sand were added to also make mortar,

This example shows very rapid strength gain is possible following long transport time and long placement time.

With the exception of the boric acid and borax, the number of grams used tomake the cement in this example and Ex. 19 are identical. Comparing these examples demonstrates the synergism between the boric acid and borax, and then between the boric acid, borax, citric acid, and potassium hydroxide. The strengths in this example increased 2,000 p.s.i., and the placement time was extended to 4 hours and 40 minutes, compared to the lesser strengths and 15 minutes in Ex. 19.

It is important to note that while there is placement time lost by holding the cementitious components in suspension over night, there is little further loss in placement time by holding the material for a week, provided sufficient borax and/or boric acid has been used.

EXAMPLE 8

(Mixing sequence 3)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    17.81                Warm water                                                                               1ST                                      30     2.14     2.82        Borax     "                                        900    64.13    84.63       Fly ash   2ND                                      45     3.21     4.23        P.C. III  "                                        45     3.21     4.23        P.C. I    "                                        90     6.41                 Ground silica                                                                            3RD                                                                            STEP 2                                   9      0.64     0.85        Boric acid                                                                               4TH                                      16.5   1.18     1.55        KOH       5TH                                      18     1.28     1.69        Citric acid                                                                              6TH                                      Water/cement ratio: 0.24                                                                            1 day    8,000  p.s.i.                                    Mixing Time:       27 min.   3 day  9,500                                                                               "                                     Transport Time:                                                                           16 hrs  30 min.   7 day 12,000                                                                               "                                     Placement Time:                                                                            2 hrs  12 min.  14 day 12,125                                                                               "                                     Total Work Time:                                                                          19 hrs  09 min.  28 day 14,500                                                                               "                                     ______________________________________                                    

After the cementitious components were mixed, the partially made cement washeld overnight. The following day, 810 grams of sand were included, before the last three components were mixed, to complete the cement and mortar.

This example compared to Ex. 9 shows how the longer placement time obtainedby mixing the citric acid last in this example, off set the loss in placement time caused by holding the mixture 16 hours and 30 minutes.

EXAMPLE 9

(Mixing sequence 4)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    17.81                Warm water                                                                               1ST                                      30     2.14     2.82        Borax     "                                        900    64.13    84.63       Fly ash   2ND                                      45     3.21     4.23        P.C. III  "                                        45     3.21     4.23        P.C. I    "                                        90     6.41                 Ground silica                                                                            3RD                                                                            STEP 2                                   9      0.64     0.85        Boric acid                                                                               4TH                                      18     1.28     1.69        Citric acid                                                                              5TH                                      16.5   1.18     1.55        KOH       6TH                                      Water/cement ratio: 0.24                                                                            1 day    6,450  p.s.i.                                    Mixing Time:       27 min.   3 day  8,900                                                                               "                                     Transport Time:     0 min.   7 day 10,050                                                                               "                                     Placement Time:                                                                           2 hrs   40 min.  14 day 11,875                                                                               "                                     Total Work Time:                                                                          3 hrs   07 min.  28 day 12,000                                                                               "                                     ______________________________________                                    

When the 90 grams of silica were mixed, 810 grams of sand were included, before the last three components were mixed to complete the cement and mortar.

There was no loss in placement time in this example, because the partially made cement was not held. Therefore, mixing the potassium hydroxide last provided almost the same placement time as Ex. 8.

The ability to make adjustments in the placement time at the place where the cement is to be used, will increase productivity by not having to waitfor cements to harden and gain strength.

At the same time, when placement times are needed, they should not be sacrificed, fearing that the rapid strength gaining cement will suddenly lose its workability.

EXAMPLE 10

(Mixing sequence 5)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    18.13                Water     1ST                                      7.2    0.52     0.69        Boric acid                                                                               "                                        900    65.28    86.67       Fly ash   2ND                                      45     3.26     4.33        P.C. III  "                                        45     3.26     4.33        P.C. I    "                                        90     6.53                 Ground silica                                                                            3RD                                                                            STEP 2                                   19.8   1.44     1.91        KOH       4TH                                      21.6   1.57     2.08        Citric acid                                                                              5TH                                      Water/cement ratio: 0.24                                                                            1 day    6,625  p.s.i.                                    Mixing Time:                                                                              22 min.           3 day  8,125                                                                               "                                     Transport Time:                                                                           0                 7 day  9,062                                                                               "                                     Placement Time:    30 sec.  14 day 10,500                                                                               "                                     Total Work Time:                                                                          22 min  30 sec.  28 day 11,500                                                                               "                                     ______________________________________                                    

As the ground silica was mixed, 810 grams of sand were added, to make mortar when the last two components were mixed to complete the cement.

Placement times ranging from 30 seconds to 17 minutes are ideal for a shot crete operation.

Few applications for structural hydraulic cements, which gain rapid strengths also want very short placement times. Special cements have been made for such applications. However, the cement of the present invention, which provides extremely long placement time, can also provide very short placement times.

EXAMPLE 11

(Mixing sequence 5)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    18.10                Water     1ST                                      10     0.72     0.96        Boric acid                                                                               "                                        900    65.15    86.42       Fly ash   2ND                                      45     3.26     4.32        P.C. III  "                                        45     3.26     4.32        P.C. I    "                                        90     6.52                 Ground silica                                                                            3RD                                                                            STEP 2                                   19.8   1.43     1.90        KOH       4TH                                      21.6   1.56     2.07        Citric acid                                                                              5TH                                      Water/cement ratio: 0.24                                                                            1 day   5,500   p.s.i.                                    Mixing Time:       22 min.   3 day 6,063 "                                     Transport Time:     0 min.   7 day 7,575 "                                     Placement Time     17 min.  14 day 7,625 "                                     Total Work Time:   39 min.  28 day 8,750 "                                     ______________________________________                                    

During the process of making the cement 810 grams of sand were added to also make mortar.

As stated earlier, the last two components added, after the introduction ofonly boric acid, provide the opposite placement time, as when the same order of mixing follows only borax or borax and boric acid, when the percent of borax is 66% or greater.

EXAMPLE 12

(Mixing sequence 5)

A cement was formed consisting, of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    18.03                Water     1ST                                      15     1.08     1.43        Boric acid                                                                               "                                        900    64.92    86.01       Fly ash   2ND                                      45     3.25     4.30        P. C. III "                                        45     3.25     4.30        P. C. I   "                                        90     6.49                 Ground silica                                                                            3RD                                                                            STEP 2                                   19.8   1.43     1.89        KOH       4TH                                      21.6   1.56     2.06        Citric acid                                                                              5TH                                      Water/cement ratio: 0.24                                                                            1 day   4,125   p.s.i.                                    Mixing Time:       22 min.   3 day 8,000 "                                     Transport Time:    0         7 day 8,125 "                                     Placement Time:                                                                           1 hr    15 min.  14 day 9,500 "                                     Total Work Time:                                                                          1 hr    37 min.  28 day 9,950 "                                     ______________________________________                                    

During the process of making the cement, 810 grams of sand were added, to also make mortar.

By comparing this example to Ex. 13, the loss of placement time caused by holding the partially made cement is very evident. The components used andmixing sequences 3, and 4 (shown before) demonstrate how this problem was solved.

EXAMPLE 13

(Mixing sequence 5)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    18.03                Water     1ST                                      15     1.08     1.43        Boric acid                                                                               "                                        900    64.92    86.01       Fly ash   2ND                                      45     3.25     4.30        P.C. III  "                                        45     3.25     4.30        P.C. I    "                                        90     6.49                 Ground silica                                                                            3RD                                                                            STEP 2                                   19.8   1.43     1.89        KOH       4TH                                      21.6   1.56     2.06        Citric acid                                                                              5TH                                      Water/cement ratio: 0.24                                                                            1 day   6,200   p.s.i.                                    Mixing Time:       22 min.   3 day 7,644 "                                     Transport Time:                                                                           15 hrs  30 min.  14 day 8,625 "                                     Placement Time:    15 min.  28 day 8,813 "                                     Total Work Time:                                                                          16 hrs  07 min.                                                     ______________________________________                                    

During the process of making the cement, 810 grams of sand were added, to also make mortar.

One hour of placement time was lost by holding (transport time) the partially made cement and partially made mortar for 15 hours and 30 minutes. Examples which follow will show the loss in placement time by long transport or suspension periods does not continue to decrease as the longer time period increases, provided enough boric acid and/or borax is used to stop the hydration process

EXAMPLE 14

(Mixing sequence 5)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    17.96                Water     1ST                                      16.5   1.19     1.57        Boric acid                                                                               "                                        900    64.65    85.54       Fly ash   2ND                                      45     3.23     4.28        P.C. III  "                                        45     3.23     4.28        P.C. I    "                                        90     6.47                 Ground silica                                                                            3RD                                                                            STEP 2                                   21.8   1.57     2.07        KOH       4TH                                      23.8   1.71     2.26        Citric acid                                                                              5TH                                      Water/cement ratio: 0.24                                                                            1 day    6,125  p.s.i.                                    Mixing Time:       22 min.   3 day  8,000                                                                               "                                     Transport Time:     0 min.   7 day  9,125                                                                               "                                     Placement Time:    24 min.  14 day 10,625                                                                               "                                     Total Work Time:   46 min.  28 day 10,775                                                                               "                                     ______________________________________                                    

During the process of making the cement, 810 grams of sand were added, to also make mortar.

EXAMPLE 15

(Mixing sequence 5)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of CHEM.&                                                           % of     CEMENTI-    COMPO-    ORDER                                    GRAMS  GRAMS    TIOUS       NENTS     MIXED                                    ______________________________________                                                                               STEP 1                                   250    17.48                Water     1ST                                      30     2.10     2.75        Boric acid                                                                               "                                        900    62.91    82.52       Fly ash   2ND                                      45     3.15     4.13        P.C. III  "                                        45     3.15     4.13        P.C. I    "                                        90     6.29                 Ground silica                                                                            3RD                                                                            STEP 2                                   34     2.38     3.12        KOH       4TH                                      36.6   2.56     3.36        Citric acid                                                                              5TH                                      Water/cement ratio: 0.23                                                       Mixing Time:       22 min.   1 day 5,375 p.s.i.                                Transport Time:                                                                           42 hrs  46 min.   7 day 6,500 "                                     Placement Time:    23 min.  14 day 8,063 "                                     Total Work Time:                                                                          43 hrs  31 min.                                                     ______________________________________                                    

After the addition of the cementitious components the partially made cementwas suspended for 42 hours and 46 minutes.

EXAMPLE 16

(Mixing sequence 6)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   250    18.24                  Water   1ST                                      6      0.44     0.58          Boric acid                                                                             "                                        900    65.67    87.33         Fly ash 2ND                                      45     3.28     4.37          P.C. III                                                                               "                                        45     3.28     4.37          P.C. I  "                                        90     6.57                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   18     1.31     1.75          Citric acid                                                                            4TH                                      16.5   1.20     1.60          KOH     5TH                                      ______________________________________                                         Water/cement ratio 0.24                                                        Mixing Time:  22 min.    1 day   7,125 p.s.i.                                  Transport Time:                                                                               0 min.    3 day   7,500 p.s.i.                                  Placement Time:                                                                              34 min.    7 day   7,750 p.s.i.                                  Total Work Time                                                                              56 min.   14 day   8,063 p.s.i.                                                          28 day   9,050 p.s.i.                                  ______________________________________                                    

EXAMPLE 17

(Mixing sequence 6)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   250    18.10                  Water   1ST                                      10     0.72     0.96          Boric acid                                                                             "                                        900    65.15    86.42         Fly ash 2ND                                      45     3.26     4.32          P. C. III                                                                              "                                        45     3.26     4.32          P. C. I "                                        90     6.52                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   21.6   1.56     2.07          Citric acid                                                                            4TH                                      19.8   1.43     1.90          KOH     5TH                                      ______________________________________                                         Water/cement ratio: 0.24                                                                                1 day   5,563 p.s.i.                                  Mixing Time:  22 min.    3 day   6,000 p.s.i.                                  Transport Time:                                                                               0         7 day   7,625 p.s.i.                                  Placement Time:                                                                              30 min.   14 day   8,063 p.s.i.                                  Total Work Time:                                                                             52 min.   28 day   8,500 p.s.i.                                  ______________________________________                                    

During the process for making the cement, 810 grams of sand were added to also make mortar.

The formulations of this example and Ex. 11 are identical. Only the order of mixing the last two components were reversed to alter the placement time.

EXAMPLE 18

(Mixing sequence 6)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   250    17.96                  Water   1ST                                      16.5   1.19     1.57          Boric acid                                                                             "                                        900    64.65    85.54         Fly ash 2ND                                      45     3.23     4.28          P.C. III                                                                               "                                        45     3.23     4.28          P.C. I  "                                        90     6.47                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   23.8   1.71     2.26          Citric acid                                                                            4TH                                      21.8   1.57     2.07          KOH     5TH                                      ______________________________________                                         Water/cement ratio: 0.24 1 day   5,188 p.s.i.                                  Mixing Time:  22 min.    3 day   6,500 p.s.i.                                  Transporting Time:                                                                           0          7 day   7,538 p.s.i.                                  Placement Time:                                                                              45 min.    14 day  8,813 p.s.i.                                  Total Work Time:                                                                             1 hr 07 min.                                                                              28 day  9,625 p.s.i.                                  ______________________________________                                    

During the process of making the cement, 810 grams of sand were added to also make mortar.

The formulations for making the cement in this example and Ex. 14 are identical. Only the order of mixing the last two components were reversed to alter the placement time.

EXAMPLE 19

(Mixing sequence 6)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   250    17.96                  Water   1ST                                      16.5   1.19     1.57          Boric acid                                                                             "                                        900    64.65    85.54         Fly ash 2ND                                      45     3.23     4.28          P.C. III                                                                               "                                        45     3.23     4.28          P.C. I  "                                        90     6.47                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   23.8   1.71     2.26          Citric acid                                                                            4TH                                      21.8   1.57     2.07          KOH     5TH                                      ______________________________________                                         Water/cement ratio: 0.24 1 day   6,000 p.s.i.                                  Mixing Time:  22 min.    7 day   7,125 p.s.i.                                  Transport Time:                                                                              19 hrs 30 min.                                                                            14 day  9,867 p.s.i.                                  Placement Time:                                                                              15 min.    28 day  9,875 p.s.i.                                  Total Work Time:                                                                             20 hrs 07 min.                                                   ______________________________________                                    

After the ground silica was mixed the process for making the cement was held 19 hours and 30 minutes (transport time). Just before the last two components were mixed, 810 grams of sand were added to also make mortar.

EXAMPLE 20

(Mixing sequence 7)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   205    16.71                  Warm    1ST                                                                    water                                            20     1.63     1.96          Borax   "                                        900    73.36    88.07         Fly ash 2ND                                      90     7.34     8.81          P.C. III                                                                               "                                                                              STEP 2                                   6.9    0.56     0.68          KOH     3RD                                      5      0.41     0.49          Citric acid                                                                            4TH                                      ______________________________________                                         Water/cement ratio: 0.20                                                       Mixing Time:  22 min.    2 day   5,063 p.s.i.                                  Transport Time:                                                                              0 min.     4 day   5,500 p.s.i.                                  Placement Time:                                                                              1 hr 07 min.                                                                              87 day  9,875 p.s.i.                                  Total Work Time:                                                                             1 hr 29 min.                                                     ______________________________________                                    

After the cementitious materials were mixed, 990 grams of sand were added to make mortar after the last two cement making components were added.

The small percent of Type III portland cement caused the hardened mortar tobecome very dense and much more abrasive resistant. In addition the portland cement extended the placement time.

EXAMPLE 21

(Mixing sequence 7)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   220    16.52                  Warm    1ST                                                                    water                                            20     1.50     1.96          Borax   "                                        900    67.57    88.07         Fly ash 2ND                                      90     6.76     8.81          P.C. III                                                                               "                                        90     6.76                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   6.9    0.52     0.68          KOH     4TH                                      5      0.38     0.49          Citric acid                                                                            5TH                                      ______________________________________                                         Water/cement ratio: 0.22                                                       Mixing Time:  22 min.    2 day   8,906 p.s.i.                                  Transport Time:                                                                              0 min.     4 day   9,800 p.s.i.                                  Placement Time:                                                                              35 min.    9 day   10,500 p.s.i.                                 Total Work Time:                                                                             57 min.                                                          ______________________________________                                    

Ground silica was added after the cementitious components were mixed. At that time 810 grams of sand were added to also make mortar.

This example was mixed in the identical manner as Ex. 20. The only difference between the two was the addition of ground silica. The placement time was cut from 1 hour and 7 minutes to 35 minutes. What was even more surprising was the increase in the early strengths. The 4 day strengths nearly doubled, and the 9 day strengths were higher than the 87 day strengths of Ex. 20.

EXAMPLE 22

(Mixing sequence 7)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   220    16.52                  Warm    1ST                                                                    water                                            20     1.50     1.96          Borax   "                                        900    67.57    88.07         Fly ash 2ND                                      75     5.63     7.34          P.C. III                                                                               "                                        15     1.13     1.47          P.C. I  "                                        90     6.76                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   6.9    0.52     0.68          KOH     4TH                                      5      0.38     0.49          Citric  5TH                                                                    acid                                             ______________________________________                                         Water/cement ratio: 0.22 2 day   6,750 p.s.i.                                  Mixing Time:  22 min.    6 day   8,050 p.s.i.                                  Transport Time:                                                                              0 min.     7 day   7,975 p.s.i.                                  Placement Time:                                                                              54 min.    28 day  9,199 p.s.i.                                  Total Work Time:                                                                             1 hr 16 min.                                                     ______________________________________                                    

When the ground silica was mixed, 810 grams of sand were added to also makemortar.

Because the ground silica had cut the placement time in Ex. 21 by 32 minutes from Ex. 20, 15 grams of Type I portland cement replaced 15 grams of Type III portland cement making the placement time of this example nearly the same as Ex. 20.

EXAMPLE 23

(Mixing sequence 7)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   270    19.10                  Warm    1ST                                                                    water                                            29     2.05     2.75          Borax   "                                        900    63.67    85.43         Fly ash 2ND                                      45     3.18     4.27          P.C. III                                                                               "                                        45     3.18     4.27          P.C. I  "                                        90     6.38                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   16.5   1.17     1.57          KOH     4TH                                      18     1.27     1.71          Citric acid                                                                            5TH                                      ______________________________________                                         Water/cement ratio: 0.26                                                       Mixing Time:  22 min.    8 day   12,000 p.s.i.                                 Transport Time:                                                                              54 hrs 0 min.                                                                             11 day  12,450 p.s.i.                                 Placement Time:                                                                              4 min.     28 day  13,375 p.s.i.                                 Total Work Time:                                                                             54 hrs 26 min.                                                   ______________________________________                                    

After the ground silica was added, the partially made cement was held 54 hours (transport time). At the end of the transport time the last two cement making components were added and mixed, then 810 grams of sand wereadded to make mortar.

EXAMPLE 24

(Mixing sequence 7)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   250    18.28                  Warm    1ST                                                                    water                                            20     1.46     1.95          Borax   "                                        900    65.83    87.61         Fly ash 2ND                                      90     6.58     8.76          P.C. I  "                                        90     6.58                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   8.25   0.60     0.80          KOH     4TH                                      9      0.66     0.88          Citric  5TH                                                                    acid                                             ______________________________________                                         Water/cement ratio: 0.24                                                       Mixing Time:  22 min.                                                          Transport Time:                                                                              0 min.     7 day    6,813 p.s.i.                                 Placement Time:                                                                              1 hr 35 min.                                                                              14 day  10,000 p.s.i.                                 Total Work Time:                                                                             1 hr 57 min.                                                                              28 day  10,625 p.s.i.                                 ______________________________________                                    

When the ground silica was mixed, 990 grams of sand were added to also makemortar.

In this example all of the Type III portland cement was replaced with Type I portland cement and the placement time was an hour longer than Ex. 21, even after increasing the citric acid and potassium hydroxide.

EXAMPLE 25

(Mixing sequence 7)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   205    16.71                  Warm    1ST                                                                    Water                                            20     1.63     1.96          Borax   "                                        900    73.36    88.07         Fly ash 2ND                                      90     7.34     8.81          Slag    "                                                                              STEP 2                                   6.9    0.56     0.68          KOH     3RD                                      5      0.41     0.49          Citric acid                                                                            4TH                                      ______________________________________                                         Water/cement ratio: 0.20 1 day   6,125 p.s.i.                                  Mixing Time:  17 min.    3 day   6,938 p.s.i.                                  Transport Time:                                                                              0 min.     7 day   7,725 p.s.i.                                  Placement Time:                                                                              1 hr 20 min                                                      Total Work Time:                                                                             1 hr 37 min.                                                     ______________________________________                                    

After the cementitious components were mixed, 990 grams of sand were added,then the last two components were mixed completing the cement and mortar.

The Type III portland cement used in Ex. 20, shown earlier, was replaced with an equal amount of slag cement. The abrasive resistance was almost identical and what was most surprising, the placement time was also.

EXAMPLE 26

(Mixing sequence 7)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   205    16.71                  Warm    1ST                                                                    Water                                            20     1.63     1.96          Borax   "                                        900    73.36    88.07         Fly ash 2ND                                      90     7.34     8.81          Slag    "                                                                              STEP 2                                   6.9    0.56     0.68          KOH     3RD                                      5      0.41     0.49          Citric acid                                                                            4TH                                      ______________________________________                                         Water/cement ratio: 0.20 1 day   4,900 p.s.i.                                  Mixing Time:  17 min.    3 day   6,125 p.s.i.                                  Transport Time:                                                                              14 hrs 25 min.                                                                            7 day   7,500 p.s.i.                                  Placement Time:                                                                              42 min.    14 day  9,650 p.s.i.                                  Total Work Time:                                                                             15 hrs 24 min.                                                                            28 day  10,100 p.s.i.                                 ______________________________________                                    

After the cementitious components were mixed the partially made cement was held for 14 hours and 25 minutes. During this time 990 grams of sand were added, then the last two components were mixed completing the cement and mortar, with the resulting placement time of 42 minutes.

EXAMPLE 27

(Mixing sequence 8)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   205    16.71                  Warm    1ST                                                                    Water                                            20     1.63     1.96          Borax   "                                        900    73.36    88.07         Fly ash 2ND                                      90     7.34     8.81          P.C. III                                                                               "                                                                              STEP 2                                   5      0.41     0.49          Citric acid                                                                            3RD                                      6.9    0.56     0.68          KOH     4TH                                      ______________________________________                                         Water/cement ratio: 0.20                                                       Mixing Time:  22 min.    3 day   4,875 p.s.i.                                  Transport Time:                                                                              0 min.     4 day   5,500 p.s.i.                                  Placement Time:                                                                              19 min.    10 day  5,563 p.s.i.                                  Total Work Time:                                                                             41 min.                                                          ______________________________________                                    

After the cementitious components were mixed, 990 grams of sand were added,then the last two components were mixed to complete the cement and make mortar.

This example is identical to Ex. 20, except the last two components were mixed in reverse order. The resulting placement time of Ex. 20 of 1 hour and 7 minutes was reduced to 19 minutes.

What is even more remarkable is when citric acid is the last component to be mixed, following only borax, the placement time is longer. But when citric acid is the last component to be mixed following only boric acid, the placement time is shorter.

EXAMPLE 28

(Mixing sequence 8)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   220    16.52                  Warm    1ST                                                                    water                                            20     1.50     1.96          Borax   "                                        900    67.57    88.07         Fly ash 2ND                                      90     6.76     8.81          P.C. III                                                                               "                                        90     6.76                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   5      0.38     0.49          Citric acid                                                                            4TH                                      6.9    0.52     0.68          KOH     5TH                                      ______________________________________                                         Water/cement ratio: 0.20                                                       Mixing Time: 31 min.     2 day   8,062 p.s.i.                                  Transport Time:                                                                             0 min.      3 day   8,188 p.s.i.                                  Placement Time:                                                                             15 sec.     4 day   8,675 p.s.i.                                  Total Work Time:                                                                            31 min. 15 sec.                                                   ______________________________________                                    

Ground silica was added after the cementitious components were mixed. At the same time, 810 grams of sand were added to also make mortar.

This example and Ex. 21 are identical formulations. Only the order of mixing the last two components were reversed to alter the placement time.

EXAMPLE 29

(Mixing sequence 8)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   220    16.52                  Warm    1ST                                                                    Water                                            20     1.50     1.96          Borax   "                                        900    67.57    88.07         Fly ash 2ND                                      75     5.63     7.34          P.C. III                                                                               "                                        15     1.13     1.47          P.C. I  "                                        90     6.76                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   5      0.38     0.49          Citric acid                                                                            4TH                                      6.9    0.52     0.68          KOH     5TH                                      ______________________________________                                         Water/cement ratio: 0.20                                                       Mixing Time:  22 min.    2 day   7,000 p.s.i.                                  Transport Time:                                                                              0 min.     7 day   9,150 p.s.i.                                  Placement Time:                                                                              9 min.     82 day  12,000 p.s.i.                                 Total Work Time:                                                                             31 min.                                                          ______________________________________                                    

When the ground silica was mixed, 810 grams of sand were added, to also make mortar.

This example is identical to Ex. 22, except the order of mixing the last two components are reversed.

Comparing this example to Ex. 28 demonstrates how precise the placement time can be tailored by altering the Type of portland cement used.

EXAMPLE 30

(Mixing sequence 8)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   250    18.28                  Warm    1ST                                                                    water                                            20     1.46     1.95          Borax   "                                        900    65.83    87.61         Fly ash 2ND                                      90     6.58     8.76          P.C. I  "                                        90     6.58                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   9      0.66     0.88          Citric acid                                                                            4TH                                      8.25   0.60     0.80          KOH     5TH                                      ______________________________________                                         Water/cement ratio: 0.20                                                       Mixing Time   22 min.                                                          Transport Time:                                                                              0 min.     9 day   9,000 p.s.i.                                  Placement Time:                                                                              50 min.    14 day  9,375 p.s.i.                                  Total Work Time:                                                                             1 hr 12 min.                                                                              28 day  10,750 p.s.i.                                 ______________________________________                                    

When the ground silica was mixed, 990 grams of sand were added to also makemortar.

This example is identical to Ex. 24, only the mixing order of the last two components were reversed to alter the placement times.

EXAMPLE 31

(Mixing sequence 8)

A cement was formed, consisting of the following:

    ______________________________________                                                % of     % of CHEM. &  COM-    ORDER                                    GRAMS  GRAMS    CEMENTITIOUS  PONENTS MIXED                                    ______________________________________                                                                               STEP 1                                   250    17.77                  Warm    1ST                                                                    water                                            20     1.42     1.87          Borax   "                                        900    63.95    84.33         Fly ash 2ND                                      130    9.24     12.18         P.C. I  "                                        90     6.40                   Ground  3RD                                                                    silica                                                                                 STEP 2                                   9      0.64     0.84          Citric acid                                                                            4TH                                      8.25   0.59     0.77          KOH     5TH                                      ______________________________________                                         Water/cement ratio: 0.23                                                       Mixing Time:  22 min.    5 day   6,563 p.s.i.                                  Transport Time                                                                               0 min.     7 day   8,650 p.s.i.                                  Placement Time:                                                                              2 hrs  0 min.                                                                             14 day  9,438 p.s.i.                                  Total Work Time:                                                                             2 hrs 22 min.                                                                             28 day  10,250 p.s.i.                                 ______________________________________                                    

When the ground silica was mixed, 990 grams of sand were added to make mortar.

This example is identical to Ex. 30, except the Type I portland cement was increased from 90 grams to 130 grams, and the placement time increased from 50 minutes to 2 hours.

EXAMPLE 32

(Mixing sequence 8)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         250    19.72               Water      1ST                                      13.5   1.07     1.33       Borax      "                                        900    71.18    88.72      Fly ash    2ND                                      90     7.12     8.87       P.C. III   "                                        STEP 2                                                                         4.5    0.35     0.44       Citric acid                                                                               3RD                                      6.4    0.51     0.63       KOH        4TH                                      ______________________________________                                         Water/cement ratio:                                                                           0.25                                                            Mixing Time:   17 min.  1 day    4,750 p.s.i.                                  Transport Time  0 min.  3 day    5,312 p.s.i.                                  Placement Time:                                                                               15 min.  7 day    6,438 p.s.i.                                  Total Work Time:                                                                              32 min                                                          ______________________________________                                    

A small percent of chemicals will provide high early strengths, but the amount of borax used would not suspend this cement more than approximately24 hours.

EXAMPLE 33

(Mixing sequence 9)

STEP 1

Before this example was carried out the potassium hydroxide and citric acidwere combined, in a dry form, and placed in a waterproof, but easy to destroy pouch. The material used for making the pouch could be included inmortar or concrete, as inert filler, without creating problems when the material hardens.

A cement was formed, consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         250    17.81               Water      1ST                                       9     0.64     0.85       Boric acid "                                        30     2.14     2.82       Borax      "                                        900    64.13    84.63      Fly ash    2ND                                      45     3.21     4.23       P.C. III   "                                        45     3.21     4.23       P.C. I     "                                        90     6.41                Ground silica                                                                             3RD                                      ______________________________________                                    

Half of the partially made cement was poured into a plastic bag. The pouch containing citric acid and potassium hydroxide was placed on top and in the center of half of the partially completed cement. The balance of the partially completed cement was poured on top. The partially made cement coagulated.

STEP 2

After waiting one week the contents were removed from the plastic bag and put in a mixer. The blades of the mixer cut through the material destroying the pouch releasing the citric acid and potassium hydroxide, which together act as an extreme water reducer thereby, immediately liquefying the coagulated mix.

    ______________________________________                                         16.5      1.18   1.55       KOH     4TH                                        18        1.28   1.69       Citric acid                                                                            "                                          ______________________________________                                    

After the cement was complete, 810 grams of sand were added and mixed 2 minutes to demonstrate that aggregates can be added after the cement is completely made.

    ______________________________________                                         Water/cement ratio:                                                                        0.24               1 day  6,400 p.s.i.                             Mixing Time:         17 mins.  3 day  9,000 p.s.i.                             Transport Time:                                                                            168 hours                                                                                0 mins.  7 day 12,000 p.s.i.                             Placement Time:      33 mins. 14 day 12,250 p.s.i.                             Total Work Time:                                                                           168 hours                                                                               50 mins. 28 day 13,000 p.s.i.                             ______________________________________                                    

It is important to note that while there is placement time lost by holding the cementitious components in suspension over night, there is little further loss in placement time by holding the material a week, provided sufficient borax and/or boric acid has been used.

This example demonstrates how the cement of the present invention would be used to make concrete, mortar or neat cement under the following conditions:

1. the people making the concrete or mortar do not have the necessary equipment, skills, or time to measure the water properly,

2. time is of essence,

3. it is difficult to transport water to where the materials will be used,

4. there are already aggregates at the location where the concrete or mortar will be made,

5. a mistake free method must be assured, and,

6. where the neat cement would be extruded into structural building components or products that would instantly take set.

Item 6, above would be achieved by using a formulation that would lose its placement time in seconds, and sand, that would abrade equipment, would not be used.

EXAMPLE 34

(Mixing sequence 10)

STEP 1

Before this example was carried out the boric acid, potassium hydroxide, and citric acid to be used in step 2 were combined, in a dry form, and placed in a waterproof but easy to destroy pouch. The material used for making the pouch could be included in mortar or concrete, as inert filler,without creating problems when the material hardens. A cement was formed, consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         266    18.89               Warm water 1ST                                      20     1.42     1.90       Borax      "                                        900    63.90    85.51      Fly ash    2ND                                      45     3.19     4.28       P.C. III   "                                        45     3.19     4.28       P.C. I     "                                        90     6.39                Ground silica                                                                             3RD                                      ______________________________________                                    

Half of the partially made cement was poured into a plastic pail. The pouchcontaining boric acid, potassium hydroxide, and citric acid was placed on top and in the middle of the partially completed cement. The remainder of the partially made cement was poured on top, which then coagulated.

STEP 2

The following day the pail of partially made cement containing the pouch was dumped into a mixer. The mixing blades cut through the material destroying the pouch releasing the boric acid, potassium hydroxide, and citric acid into the mix. While the citric acid combined with the potassium hydroxide acted as an extreme water reducer, the boric acid acted as an extreme modifying retarder, when mixed in step 2, instead of step 1.

    ______________________________________                                         8         0.57   0.76       Boric acid                                                                             4TH                                        16.5      1.17   1.57       KOH     "                                          18        1.28   1.71       Citric acid                                                                            "                                          ______________________________________                                    

It was mixed five minutes, at which time 962.5 grams of sand were added to make mortar.

    ______________________________________                                         Water/cement ratio:                                                                         0.25              1 day                                                                                6,250 p.s.i.                              Mixing Time:         17 min.   3 day                                                                                8,750 p.s.i.                              Transport Time:                                                                             13 hrs  18 min.   7 day                                                                               11,150 p.s.i.                              Placement Time:                                                                              4 hrs  37 min.  14 day                                                                               11,350 p.s.i.                              Total Work Time:                                                                            18 hrs  12 min   28 day                                                                               12,700 p.s.i.                              ______________________________________                                    

This mixing sequence would be used where long transport time, long placement and finishing time is needed followed by very rapid high early strengths for general purposes, such as building highways.

EXAMPLE 35

(Mixing sequence 10)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         255    18.15               Water      1ST                                      25     1.78     2.36       Borax      2ND                                      900    64.06    84.91      Fly ash    "                                        45     3.20     4.25       PC I       "                                        45     3.20     4.25       Slag       "                                        90     6.41                Ground silica                                                                             "                                        STEP 2                                                                         10     0.71     0.94       Boric acid 3RD                                      17     1.21     1.64       LiOH       "                                        18     1.28     1.70       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                        0.24 (ex. silica)                                                                            12 day  10,812 p.s.i.                                Mixing Time:                                                                               10 Min.      465 day  12,978 p.s.i.                                Transport Time:                                                                            39 Hrs 0 Min.                                                      Placement Time:                                                                            12 Min                                                             Total Work Time:                                                                           39 Hrs. 22 Min.                                                    ______________________________________                                    

To also make mortar 970 grams of sand were first put in the mixer followed by water and then the remaining components. Nearly ultimate strength gain was obtained in the first 12 days.

EXAMPLE 36

(Mixing sequence 9)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         250    17.29               Water      1ST                                      25     1.73     2.26       Borax      2ND                                      10     0.69     0.90       Boric acid "                                        900    62.24    81.37      Fly Ash    "                                        45     3.11     4.07       PC III     "                                        45     3.11     4.07       PC I       "                                        45     3.11     4.07       Slag       "                                        90     6.22                Ground silica                                                                             "                                        STEP 2                                                                         18     1.24     1.63       LiOH       3RD                                      18     1.24     1.63       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                        0.23 (ex. silica)                                                                           30 Hrs.   8,407 p.s.i.                                Mixing Time:                                                                               17 Min.       7 Da.   11,125 p.s.i.                                Transport Time                                                                              0 Min.      28 Da.   12,063 p.s.i.                                Placement Time:                                                                            24 Min.                                                            Total Work Time:                                                                           39 Min.                                                            ______________________________________                                    

To also make mortar 970 grams of sand were first put into the mixer. Water was then added followed by the borax, boric acid, fly ash, portland cement, slag and ground silica. Without transporting, the cementitious components, previously set-suspended in Step 1, they were activated in Step 2 by the simultaneous addition of the lithium hydroxide activator, and citric acid accelerator. Ultimate strengths of 28 days were nearly developed in 7 days.

EXAMPLE 37

(Mixing sequence 9)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         240    16.71               Water      1ST                                      25     1.74     2.26       Borax      2ND                                      10     0.70     0.90       Boric acid "                                        900    62.67    81.37      Fly ash    "                                        45     3.13     4.07       PC III     "                                        45     3.13     4.07       PC I       "                                        45     3.13     4.07       Slag       "                                        90     6.27                Ground silica                                                                             "                                        STEP 2                                                                          9     0.63     0.81       LiOH       3RD                                       9     0.63     0.81       KOH        "                                        18     1.25     1.63       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                         0.22 (ex. silica)                                                                          29 Hrs.   7,563 p.s.i.                                Mixing Time: 15 Min.      7 Da.   10,250 p.s.i.                                Transport Time:                                                                             0 Min.      28 Da.   11,375 p.s.i.                                Placement Time:                                                                             Hr. 43 Min.                                                       Total Work Time:                                                                            1 Hr. 58 Min.                                                     ______________________________________                                    

To also make mortar 970 grams of sand were first put into the mixer. The total quantity of activators was the same in Ex. 36 and Ex. 37, however, the placement time of Ex. 37 is times as long as Ex. 36. The strength comparison between Ex. 36 and Ex. 37 indicates the lithium hydroxide is a more reactive and effective activator than potassium even when more water is used. This demonstrates the difference in strength development between lithium and a combination of lithium and potassium hydroxide.

EXAMPLE 38

(Mixing sequence 9)

A cement was formed consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         240    16.61               Water      1ST                                      25     1.73     2.24       Borax      2ND                                      10     0.69     0.90       Boric acid "                                        900    62.28    80.72      Fly ash    "                                        45     3.11     4.04       PC III     "                                        45     3.11     4.04       PC I       "                                        45     3.11     4.04       Slag       "                                        90     6.23                Ground silica                                                                             "                                        STEP 2                                                                          9     0.62     0.81       LiOH       3RD                                      18     1.25     1.61       Sodium     "                                                                   carbonate                                           18     1.25     1.61       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                         0.22 (ex. silica)                                                                          27 Hrs.  4,938 p.s.i.                                 Mixing Time: 20 Min.      7 Da.   7,813 p.s.i.                                 Transport Time:                                                                             0 Min.      28 Da.   8,907 p.s.i.                                 28 Da. 8,907 p.s.i.                                                            Placement Time:                                                                             8 Hrs. 28 Min.                                                    Total Work Time:                                                                            8 Hrs. 48 Min.                                                    ______________________________________                                    

To make mortar 970 grams of sand were added at the same time as the ground silica. The only difference between Ex. 37 and Ex. 38 was twice the amountof sodium carbonate was substituted in Ex. 38 for the potassium hydroxide used in Ex. 37. Additional minutes of mixing was necessary to dissolve thesodium carbonate. Those skilled in the art will recognize that while the strengths of Ex. 38 were less than Ex. 37 and Ex. 36 they are still remarkably high for most applications. Using a combination of activators extends the placement time without having to increase the set-suspending agents.

EXAMPLE 39

(Mixing sequence 9)

A cement was formed consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         240    16.51               Water      1ST                                      25     1.72     2.22       Borax      2ND                                      10     0.69     0.89       Boric acid "                                        900    61.90    80.07      Fly ash    "                                        45     3.09     4.00       PC III     "                                        45     3.09     4.00       PC I       "                                        45     3.09     4.00       Slag       "                                        90     6.19                Ground silica                                                                             "                                        STEP 2                                                                          9     0.62     0.80       LiOH       3RD                                      27     1.86     2.40       Sodium     "                                                                   carbonate                                           18     1.24     1.60       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                         0.22 (ex. silica)                                                                           1 Da.   4,125 p.s.i.                                 Mixing Time: 20 Min.      7 Da.   6,313 p.s.i.                                 Transport Time:                                                                             0 Min.      28 Da.   7,600 p.s.i.                                 Placement Time:                                                                             5 Hrs. 51 Min.                                                    Total Work Time:                                                                            6 Hrs. 11 Min.                                                    ______________________________________                                    

To also make mortar 970 grams of sand were first put into the mixer. Ex. 39was identical to Ex. 38 except the sodium carbonate was increased 1/3rd. Again, the combination of activators provided very long placement time.

EXAMPLE 40

(Mixing sequence 9)

A cement was formed consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         235    16.42               Water      1ST                                      25     1.75     2.26       Borax      2ND                                      10     0.70     0.90       Boric acid "                                        900    62.89    81.37      Fly ash    "                                        45     3.14     4.07       PC III     "                                        45     3.14     4.07       PC I       "                                        45     3.14     4.07       Slag       "                                        90     6.29                Ground silica                                                                             "                                        STEP 2                                                                         18     1.26     1.63       LiOH       3RD                                      18     1.26     1.63       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                         0.21 (ex. silica)                                                                           3 Hrs.   4,150 p.s.i.                                Mixing Time: 15 Min.      1 Da.    8,562 p.s.i.                                Transport Time:                                                                             19 Hrs. 30 Min.                                                                             7 Da.   12,156 p.s.i.                                Placement Time:                                                                             2 Min.      28 Da.   13,000 p.s.i.                                Total Work Time:                                                                            19 Hrs. 47 Min.                                                   ______________________________________                                    

To also make mortar 970 grams of sand were put into the mixer before starting to make the cement. Ex. 40 was made identical to Ex. 36 except the water was reduced to 235 grams and rather than being activated immediately in Step 2 the set-suspended partially made cement was held 19 hours and 30 minutes. Doing so eliminated 22 minutes of placement time. The 2 minute placement time would be ideal for shot crete applications such as needed for tunnels.

EXAMPLE 41

(Mixing sequence 9)

A cement was formed consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         240    16.51               Water      1ST                                      25     1.72     2.22       Borax      2ND                                      10     0.69     0.89       Boric acid "                                        900    61.90    80.07      Fly ash    "                                        45     3.09     4.00       PC III     "                                        45     3.09     4.00       PC I       "                                        45     3.09     4.00       Slag       "                                        90     6.19                Ground silica                                                                             "                                        STEP 2                                                                          9     0.62     0.80       LiOH       3RD                                      27     1.86     2.40       Sodium     "                                                                   carbonate                                           18     1.24     1.60       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                         0.21 (ex. silica)                                                                           1 Da.    5,687 p.s.i.                                Mixing Time: 15 Min.      7 Da.    8,250 p.s.i.                                Transport Time:                                                                             25 Hrs. 0 Min.                                                                             28 Da.   10,000 p.s.i.                                Placement Time:                                                                             2 Hrs. 42 Min.                                                    Total Work Time:                                                                            26 Hrs. 57 Min.                                                   ______________________________________                                    

To also make mortar 970 grams of sand were put into the mixer before starting to make the cement. Ex. 41 was made identical to Ex. 39 except itwas not activated for 24 hours and 42 minutes. The most significant difference is demonstrated in the significant strength gain achieved--using precisely the same quantity of each component, but permitting the tempering to take place prior to activating.

EXAMPLE 42

(Mixing sequence 9)

A cement was formed consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         243    18.35               Water      1ST                                      12     0.91     1.11       Borax      2ND                                       3     0.23     0.28       Boric acid "                                        900    67.98    83.26      Fly ash    "                                        130    9.82     12.03      PC I       "                                        STEP 2                                                                         18     1.36     1.67       LiOH       3RD                                      18     1.36     1.67       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                          0.22     26 Min.    1,875 p.s.i.                                 Mixing Time:  6 1/2 Min.                                                                              30 Min.    2,437 p.s.i.                                 Transport Time:                                                                              0 Min.   45 Min.    3,200 p.s.i.                                 Placement Time:                                                                              1 1/2 Min.                                                                              60 Min.    3,900 p.s.i.                                 Total Work Time:                                                                             8 Min.   75 Min.    4,437 p.s.i.                                                         7 Da.     8,750 p.s.i.                                 ______________________________________                                    

The cementitious components together with 900 grams of sand and the appropriate amount of set-suspending agents were simultaneously mixed in water, then immediately activated with the accelerator and activator (muchas it would be done if injected & mixed in a shot crete nozzle). The mix was poured in the molds like water. Set began to take place in 11/2 minutes. Break's were made to demonstrate how fast the mix can be made to firm up and develop the strengths required to make repairs that will support highway and aircraft traffic.

EXAMPLE 43

(Mixing sequence 9)

A cement was formed consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         243    18.22               Water      1ST                                      18.5   1.39     1.70       Borax      2ND                                      6.5    0.49     0.60       Boric acid "                                        900    67.47    82.49      Fly ash    "                                        130    9.75     11.92      PC I       "                                        STEP 2                                                                         18     1.35     1.65       LiOH       3RD                                      18     1.35     1.65       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                          0.22      21 Min.   1,187 p.s.i.                                 Mixing Time:  6 1/2 Min.                                                                               30 Min.   1,563 p.s.i.                                 Transport Time:                                                                              0 Min.     7 Da.    8,375 p.s.i.                                 Placement Time:                                                                              9 Min.    28 Da.    9,750 p.s.i.                                 Total Work Time:                                                                             15 1/2 Min.                                                      ______________________________________                                    

Ex. 43 is identical to Ex. 42 except the set-suspending components were increased to extend the placement time from 11/2 minutes to 9 minutes. This demonstrates that precise placement times after activation is achievable using this invention.

EXAMPLE 44

(Mixing sequence 10)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         230    18.54               Water      1ST                                      10     0.81     0.99       Borax      "                                        900    72.55    89.06      Fly ash    2ND                                      90     7.26     8.91       PC I       "                                        STEP 2                                                                         3.5    0.28     0.35       Boric acid 3RD                                      3.5    0.28     0.35       LiOH       "                                        3.5    0.28     0.35       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                          0.23        1 Da.   6,125 p.s.i.                                 Mixing Time:  10 Min.     7 Da.   7,188 p.s.i.                                 Transport Time:                                                                              1 Hr. 30 Min.                                                                             11 Da.   7,813 p.s.i.                                 Placement Time:                                                                              5 Hr. 40 Min.                                                                             14 Da.   8,188 p.s.i.                                 Total Work Time:                                                                             7 Hr. 20 Min.                                                    ______________________________________                                    

990 grams of sand were added at the same time as the cementitious components so mortar was simultaneously made while making the cement. Ex. 44 demonstrates how effective the lithium hydroxide activator is in producing high/early strengths at a greatly reduced volume. While this cost would still be higher than activating with potassium hydroxide, the cost savings in using less accelerator and activator, while still obtaining protection against alkali reactive aggregates, creates a high-performance, New Cement which is extremely cost effective.

EXAMPLE 45

(Mixing sequence 10)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         230    18.65               Water      1ST                                      6      0.49     0.60       Borax      "                                        900    72.99    89.72      Fly ash    2ND                                      90     7.30     8.97       PC I       "                                        STEP 2                                                                         2.1    0.17     0.21       Boric acid 3RD                                      2.5    0.20     0.25       LiOH       "                                        2.5    0.20     0.25       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                         0.23             1 Da. 2,875 p.s.i.                               Mixing Time:        10 Min.   2 Da. 3,738 p.s.i.                               Transport Time:                                                                             1 Hr.  0 Min.    3 Da. 4,375 p.s.i.                               Placement Time:                                                                             2 Hr.  44 Min.                                                    Total Work Time:                                                                            3 Hr.  54 Min.                                                    ______________________________________                                    

990 grams of sand were added at the same time as the cementitious components so mortar was simultaneously made while making the cement. The higher cost lithium, having other superior benefits, can help produce an excellent general purpose cement which is approaching the cost effectiveness of Type I portland cement, by reducing the LiOH and citric acid approximately 1/3 when compared to the previous example.

EXAMPLE 46

(Mixing sequence 10)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         230    18.74               Water      1ST                                      3      0.24     0.30       Borax      "                                        900    73.35    90.27      Fly ash    2ND                                      90     7.33     9.03       PC I       "                                        STEP 2                                                                         1.5    0.12     0.15       Boric acid 3RD                                      1.25   0.10     0.13       LiOH       "                                        1.25   0.10     0.13       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                         0.23             1 Da. 2,688 p.s.i.                               Mixing Time:        10 Min.   2 Da. 3,300 p.s.i.                               Transport Time:                                                                             1 Hr.  0 Min.    3 Da. 3,800 p.s.i.                               Placement Time:                                                                             2 Hr.  18 Min.                                                    Total Work Time:                                                                            3 Hr.  28 Min.                                                    ______________________________________                                    

990 grams of sand were added at the same time as the cementitious components so mortar was simultaneously made while making the cement. The LiOH and Citric acid in Ex. 46 is approximately 1/2 as much as in Ex. 45 and yet the strength gain is still very good. Most house slabs placed in America do not require higher strengths than what was achieved in one day.

EXAMPLE 47

(Mixing sequence 10)

A cement was formed, consisting of the following:

    ______________________________________                                                         % of                                                                           CHEM.&                                                                % of     CEMENTI-              ORDER                                    GRAMS  GRAMS    TIOUS      COMPONENTS MIXED                                    ______________________________________                                         STEP 1                                                                         230    18.77               Water      1ST                                      2.5    0.20     0.25       Borax      "                                        900    73.43    90.40      Fly ash    2ND                                      90     7.34     9.04       PC I       "                                        STEP 2                                                                         1.3    0.11     0.13       Boric acid 3RD                                      0.63   0.05     0.06       LiOH       "                                        0.63   0.05     0.06       Citric acid                                                                               "                                        ______________________________________                                         Water/cement ratio:                                                                         0.23             1 Da. 2,313 p.s.i.                               Mixing Time:        10 Min.   2 Da. 3,100 p.s.i.                               Transport Time:                                                                             1 Hr.  0 Min.    3 Da. 3,225 p.s.i.                               Placement Time:                                                                             2 Hr.  8 Min.                                                     Total Work Time:                                                                            3 Hr.  18 Min.                                                    ______________________________________                                    

990 grams of sand were added at the same time as the cementitious components so mortar was simultaneously made while making the cement. The LiOH and citric acid were again reduced by 1/2 of the amount used in previous Ex. 46 test. This formulation would cost less compared to Type I portland cement without admixtures. 

What is claimed as new is:
 1. A blended hydraulic cement consisting essentially of by weight:from about 14.52 to 21.77 percent water, from about 5.00 to 23.00 percent cementitious material, from about 50.33 to 83.36 percent subbituminous fly ash, from about 0.07 to 1.25 percent boric acid, from about 0.15 to 2.80 percent borax, from about 0 to 8.00 percent ground silica, from about 0.04 to 2.83 percent citric acid, and from about 0.04 to 11.00 percent alkali metal activator, selected from the group consisting of: potassium hydroxide, potassium carbonate, sodium hydroxide, sodium carbonate, lithium hydroxide, and lithium carbonate.
 2. A blended hydraulic cement according to claim 1 wherein said cementitious material is comprised of a minimum of 5.0 percent of material selected from the group consisting of: Type I portland cement, Type III portland cement and slag cement and wherein said Type III portland cement and slag cement together comprise no more than 12.0 percent by weight of the total cement.
 3. The blended hydraulic cement of claim 1 wherein the alkali metal activator is lithium hydroxide of about 0.06 to 2.55 percent by weight of the total cement.
 4. A mortar formed from the blended hydraulic cement of claim 1 including sand in a weight ratio to cement forming constituents of 0.25-4.0:1.
 5. The blended hydraulic cement of claim 1 consisting essentially of by weight:from about 17.51 to 18.36 percent water, from about 6.31 to 12.60 percent cementitious material, from about 53.00 to 67.57 percent subbituminous fly ash, from about 0.10 to 1.00 percent boric acid, from about 0.20 to 2.00 percent borax, from about 0 to 6.30 percent ground silica, from about 0.14 to 1.90 percent citric acid, and from about 0.14 to 6.80 percent alkali metal activator.
 6. A blended hydraulic cement of claim 1, wherein more than one alkali metal activator is used.
 7. A blended hydraulic cement consisting essentially of by weight:from about 14.52 to 21.77 percent water, from about 5.00 to 22.97 percent cementitious material, from about 50.31 to 83.25 percent subbituminous fly ash, from about 0.10 to 1.35 percent boric acid, from about 0 to 7.99 percent ground silica, from about 0.04 to 2.83 percent citric acid, and from about 0.04 to 11.03 percent alkali metal activator, selected from a group consisting of: potassium hydroxide, potassium carbonate, sodium hydroxide, sodium carbonate, lithium hydroxide and lithium carbonate.
 8. A blended hydraulic cement according to claim 7 wherein said cementitious material is comprised of a minimum of 5.0 percent of material selected from the group consisting of: Type I portland cement, Type III portland cement and slag cement and wherein said Type III portland cement and slag cement together comprise no more than 12.0 percent by weight of the total cement.
 9. The blended hydraulic cement of claim 7 wherein the alkali metal activator is lithium hydroxide of about 0.06 to 2.55 percent by weight of the total cement.
 10. A mortar formed from the blended hydraulic cement of claim 6 including sand in a weight ratio to cement forming constituents of 0.25-4.0:1.0.
 11. The blended hydraulic cement of claim 7 consisting essentially of by weight:from about 17.51 to 18.36 percent water, from about 6.31 to 12.60 percent cementitious material, from about 53.00 to 67.57 percent subbituminous fly ash, from about 0.12 to 1.00 percent boric acid, from about 0 to 6.30 percent ground silica, from about 0.14 to 1.90 percent citric acid, and from about 0.14 to 6.80 percent alkali metal activator.
 12. The blended hydraulic cement of claim 7 wherein more than one alkali metal activator is used.
 13. A blended hydraulic cement consisting essentially of by weight:from about 14.52 to 21.77 percent water, from about 5.00 to 22.97 percent cementitious material, from about 50.30 to 83.25 percent subbituminous fly ash, from about 0 to 7.98 percent ground silica, from about 0.20 to 2.95 percent borax, from about 0.04 to 2.85 percent citric acid, and from about 0.04 to 11.05 percent alkali metal activator, selected from a group consisting of: potassium hydroxide, potassium carbonate, sodium hydroxide, sodium carbonate, lithium hydroxide, and lithium carbonate.
 14. A blended hydraulic cement according to claim 13 wherein said cementitious material is comprised of a minimum of 5.0 percent of material selected from the group consisting of: Type I portland cement, Type III portland cement and slag cement and wherein said Type III portland cement and slag cement together comprise no more than 12.0 percent by weight of the total cement.
 15. The blended hydraulic cement according to claim 13 wherein the alkali metal activator is lithium hydroxide of about 0.06 to 2.55 percent by weight of the total cement.
 16. A mortar formed from the blended hydraulic cement of claim 13 including sand in a weight ratio to cement forming constituents of 0.25-4.0:1.0.
 17. The blended hydraulic cement of claim 13 consisting essentially of by weight:from about 17.51 to 18.36 percent water, from about 6.31 to 12.60 percent cementitious material, from about 53.00 to 67.57 percent subbituminous fly ash, from about 0.25 to 2.00 percent borax, from about 0 to 6.30 percent ground silica, from about 0.04 to 1.90 citric acid, and from about 0.04 to 6.80 percent alkali metal activator.
 18. The blended hydraulic cement of claim 13, wherein more than one alkali metal activator is used. 